• 비파괴검사학회지
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• 제5권2호
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• pp.53-57
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• 1986

이상적인 검사는 합부판정 기준보다 큰 결함을 100%검출, 불합격시키고 그보다 작은 결함은 100% 합격시킬 수 있으나 현실적으로 이는 불가능하고 검사의 본질적인 불확실성으로 인해 때로는 합격되어야 할 결함이 불합격으로 처리되거나 (TYPE 1 ERROR라 칭함) 불합격되어야 할 결함이 합격으로 처리되기도 한다. (TYPE 2 ERROR) TYPE 1 ERROR 및 TYPE 2 ERROR를 동시에 줄이기 위해서는 검사의 불확실성을 제거하여야 하며 주어진 합부판정 기준과 검사불확실성하에서 검사를 둘러싼 총경비를 최소화시키기 위하여는 TYPE 1 ERROR와 TYPE 2 ERROR의 확률 및 그로 인한 예상 경비를 관련시켜야 한다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.1380-1383
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• 2004

The scanning type XY stage is frequently used these days as precision positioning system in equipment for semiconductor or display element. It is requested higher velocity and more precise accuracy for higher productivity and measuring performance. The position accuracy of general stage is primarily affected by the geometric errors caused by parasitic motion of stage, misalignments such as perpendicular error, and thermal expansion of structure. In the case of scanning type stage, H type frame is usually used as base stage which is driven by two actuators such as linear motor. In the point view of scanning process, the stage is used in moving motion. Therefore, dynamic variation is added as significant position error source with other parasitic motion error. Because the scanning axis is driven by two actuators with two position detectors, 2 dimensional position errors have different characteristic compared to general tacked type XY stage. In this study 2D position error of scanning stage is analyzed by 1D heterodyne interferometer calibrator, which can measure 1D linear position error, straightness error, yaw error and pitch error, and perpendicular error. The 2D position error is evaluated by diagonal measurement (ISO230-6). The yaw error and perpendicular error are compensated on the base stage of scanning axis. And, the horizontal straightness error is compensated by cross axis compensation. And, dynamic motion error in scanning motion is analyzed.

• Nuclear Engineering and Technology
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• 제23권2호
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• pp.174-182
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• 1991

안전계통의 이용불능도 및 최적시험주기 평가에 있어서 주기적인 시험과 관련된 인간실수의 영향을 고려하였다. 시험 및 보수와 관련된 인간실수는 건전한 계통이 시험 후 잘못된 상태에 놓이게 될 가능성과(Type A인간실수)건전하지 못한 계통이 시험시 감지되지 못할 가능성(Type B인간실수)이다. 계통이용불능도 및 최적시험주기에 미치는 인간실수의 영향을 결정하기 위하여 안전계통의 이용불능도를 계산하기 위한 사상수목모델이 개발되었다. 또한 안전주입계통의 신뢰도 분석을 통하여 계통전체에 미치는 영향을 평가하였다. 다양한 민감도 분석 결과, (1) 계통이용불능도는 인간실수의 확률이 커질수록 증가하며 Type A인간실수의 영향이 훨씬 크다. (2) 최적시험주기 는 Type A 인간실수가 커 질수록 약간 증가하나, Type B 인간실수가 커 질수록 감소한다. (3) 안전주입펌프의 시험주기를 고정시키면 안전주입계통의 이용불능도는 Type A인간실수가 커질수록 크게 증가하나 Type B 인간실수가 커지더라도 약간 증가한다. 따라서 인간실수의 영향을 고려 할 때 계통의 이용불능도를 일정 수준으로 유지하기 위해서는 시험주기(최적시험주기가 아님 )를 줄여야 한다. 그리고 시험 및 보수시 Type A 인간실수는 계통의 이용불능도에 미치는 영향이 크므로, 특히 TyPe A 인간실수를 줄이기 위한 노력이 필요하다.

• 제어로봇시스템학회논문지
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• 제18권5호
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• pp.502-508
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• 2012

Heliostat, as a concentrator to reflect the incident solar energy to the receiver, is the most important system in the tower-type solar thermal power plant since it determines the efficiency and ultimately the overall performance of solar thermal power plant. Thus, a good sun tracking ability as well as a good optical property of it are required. Heliostat sun tracking system uses usually an open loop control system. Thus the sun tracking error caused by heliostat's geometrical error, optical error and computational error cannot be compensated. Recently use of sun tracking error model to compensate the sun tracking error has been proposed, where the error model is obtained from the measured ones. This work is a development of heliostat sun tracking error measurement and compensation method using BCS (Beam Characterization System). We first developed an image processing system to measure the sun tracking error optically. Then the measured error is modeled in linear polynomial form and neural network form trained by the extended Kalman filter respectively. Finally error models are used to compensate the sun tracking error. We also developed the necessary image processing algorithms so that the heliostat optical properties such as maximum heat flux intensity, heat flux distribution and total reflected heat energy could be analyzed. Experimentally obtained data shows that the heliostat sun tracking accuracy could be dramatically improved using either linear polynomial type error model or neural network type error model. Neural network type error model is somewhat better in improving the sun tracking performance. Nevertheless, since the difference between two error models in compensation of sun tracking error is small, a linear error model is preferred in actual implementation due to its simplicity.

• 한국지능시스템학회:학술대회논문집
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• 한국지능시스템학회 2007년도 추계학술대회 학술발표 논문집
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• pp.183-186
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• 2007

We introduction some properties for fuzzy power function of performance of a test. First we define fuzzy type I error and type II error for the probability of the two types of error. And we show that an fuzzy error probability of one kind can only be reduced at cost of increasing the other fuzzy error probability.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.805-808
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• 2005

This paper is a study on an optical bench satisfying stiffness and thermal pointing error requirements for LEO earth observation satellite. According to shape and stiffness requirements, optical bench type 1 is designed. Because type 1 does not satisfy the thermal pointing error requirement, an optical bench type 2 is suggested. Although the type 2 has better results than type 1, it still does not meet the thermal pointing error requirement. Using the results of optical bench type 1&2, the optical bench type 3 is finally designed, which satisfies both the stiffness and thermal pointing error requirements.

• 한국안전학회지
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• 제22권4호
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• pp.66-71
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• 2007

Human error is one of the major contributors to the railway accidents or incidents. In order to develop an effective countermeasure to remove or reduce human errors, a systematic analysis should be preferentially performed to identify their causes, characteristics, and types of human error induced in accidents or incidents. This paper introduces a case study for human error analysis of the railway accidents and incidents. For the case study, more than 1,000 domestic railway accidents or incidents that happened during the year of 2004 have been investigated and a detailed error analysis was performed on the selected 90 cases, which were obviously caused by human error. This paper presents a classification structure for human error analysis, and summarizes the analysis results such as causes of the events, error modes and types, related worker, and task type.

• 한국데이터정보과학회:학술대회논문집
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• 한국데이터정보과학회 2004년도 추계학술대회
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• pp.17-23
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• 2004

At the conclusion from the hypothesis testing, there is a possibility of making Type I error and Type II error. The purpose of this article is to use this program in statistics teaching through developing the program for studying on the concept about these two errors, two kinds of the probability of errors by the variation of rejection region, two kinds of the probability of errors by the variation of sample size, the relations of the probability $\alpha$ and $\beta$ by these two errors, and power function, power curve.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.177-177
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• 2000

In this paper, we propose a two-input two-output fuzzy controller to improve the performance of transient response and to eliminate the steady state error. The outputs of this controller are the control input calculated by position-type fuzzy controller and the accumulated error scaling factor. Here, the accumulated error scaling factor is adjusted on-line by fuzzy rules according to the current trend of the controlled process. To show the usefulness of the proposed controller, it is applied to several systems that are difficult to get satisfactory response by conventional PD controllers or PI controllers.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2011년도 추계학술대회
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• pp.123-133
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• 2011

This paper reviewed the relationship between job stress and human error, and the moderating effect of age and maintenance type on the relationship between job stress and human error in maintenance personnel. Based on the responses from 450 maintenance personnels, the results of multiple regression analysis showed that physiological and psychological stress responses have positively related with human error. In moderating effect test, age appeared to impact on the relationship between physiological/behavioral stress and human error.